Second: the next trick is to repair .Net 2, which is a part of some Windows operating systems and which cannot be removed and reinstalled like a program. Or at least it can, but by non-trivial means.

Full re-installation is delicate, as you have to manually remove the files and registry entries, or use a tool that erases all .Net and then reinstall the lot, plus all the updates and security fixes. That takes at least three re-boots and more visits to Microsoft updates.

This radical clean up tool is described here:

(I have removed h t t p / / : and put spaces after the dots because this site won't let me post URLs. How useful of it. )

blogs. msdn. com /b/astebner/archive/2008/08/28/8904493.aspx

A simpler approach is to download the most recent .Net 2.2 files, which is at:

three doubleUs . microsoft. com /download/en /details.aspx?displaylang=en&id=1639
(NB substitute for three doubleUs: same reason as above.)

You want a file called NetFx20SP2_x86.exe

Do not install this. Instead, unzip it with e.g. WinZip into a prepared folder, for example c:\Temporary, which I have called [YF] below. This gives a complex tree structure, which you should open fully to find

[YF]\wcu\dotNetFramework\dotNetFX20\Netfx20a_x86.msi

Where [YF] is the folder into which you unzipped the archive, as above. Leave that window open, but go to:

Start> Settings> Control panel> Add or Remove Programs

Locate Microsoft .Net Framework 2 Service Pack 2

Click on "Click here for support information" and NOT on Change or Remove

A rough looking panel comes up, offering Repair or Close. Click on Repair and it will prompt for the location of the Netfx20a_x86.msi file, which is as shown above.

Browse to that and tell it to continue. It repairs - whatever that actually means - .Net 2 SR 2. You must reboot, to much background activity when Windows next starts.

... which may or may not get your Desktop software going, Harkness with the strangely attractive dobermann eyes, or it may not. If it does not, then it is about a day's worth of reinstallation of the entire .Net structure, its updates and other little tweaks. During which you may lose Windows. Thanks, Research Immotile.